Chinese is spoken by almost 90 corer people. It is mother tongue of the largest number of people, if one could use this yardstick for deciding the greatest language on the earth. But outside China not many people know this. Though English is spoken in England, the United States, Canada and Australia, it is mother tongue to less than 45 crore people. But going by the users, English may be the most used language as nearly all educated people in South Asia, the Middle East and in most parts of Africa use English in some or the other way.
Currently, seven languages of the world are considered to be the most used languages internationally. Looked from the angle of mother tongue as well as the wide use, these seven languages could be put into that category: Chinese, English, French, Spanish, Arabic, Russian, Hindi, and Japanese.
According to the UNESCO, there are more than 6,000 languages spoken around the world. But several of them are dying due to disuse. It is said ultimately, every single person would have to learn at least one of the above seven languages if he intends to carry international business or conduct research or be employed anywhere in the world.